Developed for the Office of Naval Research in 2009, this vehicle was designed to conduct ocean underwater surveillance, enabling it potentially to detect chemical spills, monitor the presence of ships and submarines, and observe the migration of schools of fish.
Recently, a team at VirginiaTech has improved the performance of this silicone swimmer, enabling it to better overcome the limitations of its artificial skin and better mimic the true motion of a jellyfish. Details on this new design and how it might provide new insights into jellyfish propulsion mechanisms will be presented at the 2011 meeting of the American Physical Society’s Division of Fluid Dynamics in Baltimore, Md., Nov. 20-22.
According to VirginiaTech mechanical engineer Alex Villanueva, Robojelly looks very similar to an actual jellyfish. “Its geometry is copied almost exactly from a moon jellyfish [Aurelia aurita],” he said. The robot is built out of silicone and uses shape memory alloy (SMA) actuators to swim.
To move through the water, the natural animal uses the bell section of its body, which deforms and contracts to provide thrust. The lower, or lagging, section of the bell is known as the flexible margin, and it deforms slightly later in the swimming process than the rest of the bell. Until recently, however, Robojelly lacked this crucial piece of anatomy in its design.
Villanueva and his colleagues tested a number of different designs for their robot, some with and without an analog to a flexible margin. Initially, the artificial materials used in construction presented a problem. Unlike their natural counterparts, the artificial materials tended to fold as they deformed, reducing Robojelly’s performance. After testing a number of designs and lengths for the folding margin, the engineers discovered that cutting slots into the bell reduced this unwanted folding effect.
This gave Robojelly a truer swimming stroke, as well as a big boost in speed.
“These results clearly demonstrate that the flap plays an important role in the propulsion mechanism of Robojelly and provides an anatomical understanding of natural jellyfish,” said Villanuerva.
The talk, “Effects of a flexible margin on Robojelly vortex structures,” is at 3:05 p.m. on Tuesday, Nov. 22, 2011, in Room 324. Abstract: http://absimage.aps.org/image/MWS_DFD11-2011-001706.pdfMORE MEETING INFORMATION
Charles Blue | Newswise Science News
Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs
07.11.2017 | Technische Universität München
NRL clarifies valley polarization for electronic and optoelectronic technologies
20.10.2017 | Naval Research Laboratory
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
22.11.2017 | Business and Finance
22.11.2017 | Physics and Astronomy
22.11.2017 | Physics and Astronomy